Countess Elizabeth Báthory de Ecsed (1560–1614) was a Hungarian noblewoman and serial killer in the Kingdom of Hungary.
She and four collaborators were arrested in 1610 and accused of torturing and killing hundreds of girls and women over the preceeding twenty years. Her guilt was confirmed by the testimony of more than 300 witnesses and survivors as well as considerable physical evidence.
The tales describing that she bathed in the blood of virgins to retain her youth, were generally recorded years after her death, and are unreliable. Nevertheless, her story quickly became part of national folklore, and her infamy persists.
She is often categorised as vampiric, but the ritual of bathing in blood strikes me as a form of attemopted witchcraft.